Automatically-adjustable wrench



I. J. GALBRAITH.

AUTOMATICALLY ADJUSTABLE WRENCH.

Patented June 27, 1922.

ISAAC J. GALBRAITH, OF CHICAGO, ILLINOIS.

AUTOMATICALLY-ADJUSTABLE WRENCH.

Specification of Letters Patent. 7 Patented J 2'? 1922" Application filed September 8, 1919. Serial No. 322,335. 7

T 0 all whom it may concern Be it known that I, Ismxo J. GALBRAITH, a resident of Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Automatically- Adjustable Trenches, of which the follow ing is a specification.

This invention relates to wrenches. Its object is to provide a wrench which combines the functions of an ordinary monkey wrench and of a pipe or so-called Stilson wrench, and in which the movable jaw is automatically adjustable toward and from the stationary jaw to adapt the wrench to operate on nuts or rounds of different sizes.

The invention comprises the construction and arrangement of parts hereinafter de scribed and claimed.

In the accompanying drawing Fig. 1 is a plan view of a wrench showing one embodiment of the invention; Fig. 2 is a side view of the same; and Flgs. 3, 4 and 5 are cross sectional views taken respectively on the lines 3-3, 44, and 55, Fig. 2.

The wrench illustrated comprises a body portion or head 1 which is either integral.

with or secured to a suitable handle 2 and which body portion is provided with the fixed jaw face 3, which preferably is curved, as shown, with its maximum outward projection at one side of the longitudinal central line of the head and handle, and curving thence to a minimum outward projection on the opposite side of the longitudinal central line of the head and handle. In other words, the upper portion of the jaw face 3, as viewed in Fig. 2, is at its maximum distance from the axis of the head 1 towards which it gradually curves and crosses at its lower extremity, by said axis being meant a line pass ing through the pivotal point 4 perpendicular to the center line of the handle 2. Pivotally connected to the body 1, such as by a pin 4, is a movable member comprising the curved arm 5 terminating in a downwardly projecting hooked portion 6 provided on its inner face with a jaw face 7 which is spaced from and cooperates with the jaw face 3 on the body 1. The pivotal point 4 of the movable jaw is eccentric to the fixed jaw face 3, and consequently the distance between the two jaw faces will vary by a mere change in the angular position of the movable arm 5 relative to the body 1. Figs. 1 and 2 show substantially the maximum distance between the two jaw faces, but it is apparent that as the movable jaw member is moved downwardly, the distance between the aw faces 7 and 3 will be decreased, until at the point of nearest approach the ends of the two jaw faces substantially contac This angular movement of the movable jaw member takes place entirely automatically, merely by gravity, and without the necessity of adjusting screw connections as in monkey and so-called Stilson wrenches. Preferably the two jaw faces will be serrated as illustrated, so as to grip a round object, such as a pipe or rod, as well as a non-circular body, such as a nut.

Preferably the body or head 1 will be slotted as shown at 8, to receive therein the arm 5, the slot 8 being out down far enough to permit the end of the movable jaw to move substantially into contact with the end of the fixed jaw. This gives a very strong con struction, one which cannot be strained to such an extent as to lose a proper grip upon a plpe or rod.

In the use of the wrench, it is engaged with a rod or! tube by merely hooking the wrench over the rod or tube, the movable jaw 6 automatically dropping by gravity to its proper adjusted position to grip the rod or tube. To apply the wrench to a nut or the like, it may be necessary to use the fingers to position the jaws on the nut, but after being so positioned the movable jaw automatically drops by gravity to take a firm grip upon the nut. The wrench therefore is always ready for use no matter what the size of the article to be gripped may be, without the necessity of adjustment.

The wrench obviously can be made in various sizes as required by the various trades and professions, but each size obviously is capable of gripping a considerable range of sizes of rods, tubes or nuts.

The construction is Very simple and strong and can be used without straining the same to the extent where it will slip, and is very durable. It can be readily fabricated of steel or other strong metal of the necessary strength and cannot be readily broken.

I claim: I

A wrench, comprising a handle having a head provided at its end with a gripping face, a freely movable arm pivoted to the head at one side of the center line of the handle and provided at its extreme outer end with a straight gripping face, said gripping face on the head gradually curving from a gagged between the gripping faces by alateral 10 point beyond the pivotal point of said arm striking blow of the wrench.

towards and interseoting an axis line which In testimony whereof, I have hereunto set passes through said pivotal point and which my hand.

is perpendicular to said center line, the angularity between the two gripping faces when the wrench is in wide open position Witnesses: being such as to afford an unobstructed space ALIoE A. TRILL,

ISAAC J. GALBRAITH.

between them whereby an article may be en- HOWARD T. SNIVELY. 

